Hi there, I have a problem with minimizing energy of system in lammps. I tried different minimize methods but they do not give me desired results. I saw people made good results with cg minimization in literature with the same potentials but it does not work in my simulations.

Geometry of system does not matter and it does not minimize its energy despite how I place atoms. I use potentials for Fe and He.

Here is fragment of my lammps code:

# ---------- Initialize Simulation ---------------------

clear

units metal

dimension 3

boundary p p p

atom_style atomic

# ---------- Create Atomistic Structure ---------------------

lattice bcc 3

region whole block 0.000000 13.41640786 -67.08203932 67.08203932 0.000000 6 units box

create_box 3 whole

region upper block INF INF 0.000000 INF INF INF units box

lattice bcc 3 orient x 0 1 -2 orient y 0 2 1 orient z 1 0 0

create_atoms 1 region upper

region lower block INF INF INF 0.0 INF INF units box

lattice bcc 3 orient x 0 1 2 orient y 0 -2 1 orient z 1 0 0

create_atoms 2 region lower

group upper type 1

group lower type 2

lattice fcc 3.3 orient x 1 0 0 orient y 0 1 0 orient z 0 0 1

region hel block INF INF -1 4 INF INF units box

# region hel2 block INF INF 66 68 INF INF units box

create_atoms 3 region hel

# create_atoms 3 region hel2

group hel region hel

# group hel2 region hel2

group lower region lower

group upper region upper

group upper type 1

group lower type 2

group hel type 3

# ---------- Define Interatomic Potential ---------------------

pair_style hybrid table linear 3027 beck 8.0 eam/alloy

pair_coeff * * eam/alloy FeCr.eam.alloy Fe Fe Fe

mass 3 4.002602

pair_coeff 1 3 table HeFe.pot MORSE_FE_HE 6.0

pair_coeff 2 3 table HeFe.pot MORSE_FE_HE 6.0

pair_coeff 3 3 beck 398.7 0.0000869 0.675 4.390 0.0003746 6.0

neighbor 5.0 bin

neigh_modify delay 10 check yes

# ---------- Displace atoms and delete overlapping atoms -----

displace_atoms upper move 0 0 0 units lattice

delete_atoms overlap 1.5 lower upper

delete_atoms overlap 1.5 upper hel

delete_atoms overlap 1.5 lower hel

write_data krysztal.txt

# ---------- Define Settings ---------------------

compute csym all centro/atom fcc

compute eng all pe/atom

compute eatoms all reduce sum c_eng

# ---------- Run Minimization ---------------------

reset_timestep 0

thermo 10

thermo_style custom step pe lx ly lz press pxx pyy pzz c_eatoms

fix 1 all box/relax iso 0 vmax 0.001

fix_modify 1 energy yes

dump 1 all cfg 25 dump.sig5_minimization_*.cfg id type xs ys zs c_csym c_eng fx fy fz

dump_modify 1 element Fe Fe He

min_style cg

minimize 1e-115 1e-115 15000 15000

undump 1

I appreciate every advice.

Thank you in advance.